US2490667A

US2490667A - Dual-speed phonograph turntable drive utilizing two motors

Info

Publication number: US2490667A
Application number: US45720A
Authority: US
Inventors: Jr Wilton E Boyd
Original assignee: Alliance Manufacturing Co Inc
Current assignee: Philips Home Products Inc
Priority date: 1948-08-23
Filing date: 1948-08-23
Publication date: 1949-12-06
Anticipated expiration: 1966-12-06

Description

Dec. 6, 1949 w. E. BOYD, JR

DUAL-SPEED PHONOGRAPH TURNTABLE DRIVE UTILIZING TWO IOTORS Filed Aug. 23, 1948 .2 Sheets-Sheet 1 Qwuwwtoo WILTON E.- BOYD, JR.

i 3 m fi wfw. E. BOYD, JR 2,490,667

DUAL S FEED PHONOGHAPH TURNTABLE DRIVE UTILIZING TWO MOTORS Filed Aug. 23, 1948 2 Sheets-Sheet 2 l9 W 1' l2 WILTON E. BQYD,JR.

MXW- 6 Patented Dec. 6, 1949 DUAL-SPEED PHON O GRAPH TURN TABLE DRIVE UTILIZING TWO.MOTORS Wilton E. Boyd, Jn,

Alliance, Ohio, assi nor to The Alliance Manufacturing :Company, Alliance, Ohio, a corporation of Ohio Application August '23, 1948,'Serial No. 45;720

9 Claims.

This invention relates to driving mechanisms for phonograph turntables and more particularly to apparatus for driving a turn-table at eitherone of two selected speeds. It has heretofore been proposed for this purpose to employ a pair of identical electric motors and to provide a speedreducing driving interconnection between each of the .motors and thetu-rntable for selective conditioning whereby the turntable may be driven at either one of two predetermined speeds. Normally the driving interconnections between the motors :and'turnta'bles in phonograph assemblies include rubber tired idling -:or friction wheels arranged to contact :meital pulleys on the motor shafts and metal flanges :on .the turn-tables. Due to the speed reduction required the diameters "of the motor pulleys are quite small and if an assembly is allowed to set for any "appreciable length of time with the motor pulley in pressure contact with therubber tire of the idling wheel a permanent set or indentation may result in the periphery of the tire, which makes for uneven subsequent operation. This difliculty also results, but to a lesser extent, if the friction wheels are allowed to stand in pressure contact withthe turntable flange. It is accordingly desirable that the motor pulley be moved :away from the idling wheel or vice versa when the assembly is not in use and in the case of a dual-speed assembly utilizing two motors and two associated idling wheels it is desirable that the motor pulley of the idle motor be moved away from the :associated idling wheel or 'vice versa even when the companion drive is in operation. It is also desirable that the idling or friction wheels :bEIIIOVfid away from the turntable flange when the wheels are not in use.

The primary object 'of the present invention is the provision of a simple and practical mechanical arrangement in a dual-speed phonograph drive employing a pair of motors and a pair of associated idling wheels for automatically disengaging both the motor pulleys from the idling wheels when neither drive is in use, and for automatically disengaging the pulley :of the idle motor from its associated .idling wheel when the companion drive is in operation.

A more specific object of the invention is the provision of an improved apparatus for accomplishing the above mode of operation and in accordance with .my preferred embodiment of such apparatus the same comprises an improved mounting means tor the carriers of the idling wheels whereby a unitary shiitable member may be employed to selectively move both the wheels 7 pair .of electric motors ll and out of engagement with their motor pulleys and the turntable flange, or one or the-other of said wheels out of such engagement while the companion wheel is allowed to have yielding driving interconnection between its companion motor pulley and the turntable. flange.

Yet a further object of the invention is the provision in apparatus LQf the general character outlined above of an improved unitary operating member for such shiftablemember and of .anlimproved arrangement for selectively energizing the motors in response to movement of said operating member.

The above and other objects :and advantages of the invention will :become apparent .upon consideration of the following detailed specification and the accompanying drawing wherein there is disclosed a preferred embodiment of the invention.

. In the drawing;

Figure 1 is .a plan view of a phonograph turntable drive constructed in accordance with the principles .of my invention;

Figure 2 is azside elevation of the apparatus of Figure 1.;

Figure 3 is a vertical section taken along the line III-1110f Figure .1;

Figure .4 is a partial ,plan view, on an enlarged scale, of the apparatus ofFigure 1 and Figure 5 is a fragmentary vertical section taken along the line VV of Figure .4.

Referring to the drawing in detail, the refer ence numeral 10 designates a mounting plate which carries, in depending .relation therewitha l2. Also supported on the plate 1:0 .is a bearing mount 1'3 to rotatably support a turntable 14. In .accordance with usual practice, the turntable .14. is .formed with a depending peripheral flange 15.

The shafts of the motors H and I2 extend vertically up through apertures formed in the plate H) as shown more clearly in Figure 5. Annular portions of the plate I!) immediately surrounding such apertures are raised upwardly from the principal "surface of the plate -10 to provide hearingsurfaces Hi for the idling wheel carrying members now to be described. Received in such aperture-s are ferrules I! each having *a wide upper flange spacedupwardly from the bearing surface l6 and interposed between these flanges and the "bearing surfaces 118 are the carrier plates f8. Eachof the plates 1*8'is to receive the shank of the ferrule 17 and this aperture is elongated in the longitudinal direc-- tion of the carrier plate to allow the plate to have formed with an aperture longitudinal sliding movement relative to the axis of the ferrule H.

Secured in the outer free end of each of the carrier plates i8 is a bearing l9 which rotatably supports a shaft mounting a wheel 2| on which is aifixed a peripheral tire 22 preferably made of rubberl The carrier plates l8 areeach formed at their outer free extremity with an integral upwardly directed lug 23 to which is connected one end of a tension coil spring 24, the other end of which is fastened to the mounting plate II). By referring to Figures 1 and 4, it will be noted that the directions of the springs 24 are such that the carriers H! are biased to such rotational and longitudinal positions that the friction or idling wheels 2|, 22 are maintained in yieldable engagement with both the inner surface of the turntable flange I5 and with the motor pulleys which are carried by the upper ends of the motor shafts which project upwardly through the ferrule I? a as indicated more clearly in Figures 2 and 5. The shaft of motor H is provided with a small diametered pulley 25 while the shaft of motor I2 is provided with a large diametered pulley 26. The speed of the turntable M is, of course, determined by which of the motors has operative driving interconnection with the turntable, The shifting means for transfering the drive from one motor to the other will now be described.

Slidably mounted on the plate It is a flat link 2! having a pair of olfset but diametrically opposed end portions 28 each formed with a slot 29 to receive a flanged guide stud 3! which is secured to and projects upwardly from the mounting plate l0. Link 21 is also formed with a centrally disposed elongated aperture 3| to receive the bearing mount i3. While not shown, annular portions of the plate l0 immediately surrounding the shanks of the studs 30 are raised upwardly from the general plane of the plate I0, in the manner suggested by the bearing |6 of Figure 5, to position the link 21 in the same plane with the carriers l8. An outer corner of each of the carriers [8 is formed with an integral rounded tab 32 arranged to be engaged by a rounded corner 33 of the end portions 28 of the link 21 and to slide along a side edge of the portion 28 adjacent to the corner 33. This side edge is formed with an inclined shoulder and beyond the shoulder the side edge is arranged to be engaged by the inner corner of the carrier |8 upon the link section 28 being moved radially outward to engage and move the link It.

The operation of the apparatus described immediately above may be better understood by comparing the left half portion of Figure 1 with Figure 4. Thus, in Figure 1 the carrier I8 is free to rotate and to slide longitudinally on the ferrule H and consequently the spring 24 acts to yieldably retain the friction wheel 2|, 22 in driving contact with both the turntable flange I5 and the motor pulley 25. Assuming the motor I! to be energized the turntable will be driven at a speed determined by the ratio of the diameters of the motor pulley 25 and the tire 22. If now the link 21 is shifted to the left the rounded corner 33 of the end portion 28 will engage the mounted tab 32 of the carrier l8 and the carrier will be rotated in a clockwise direction towithdraw the wheel 2|, 22 from the flange l5. As the carrier rotates its inner rounded corner will engage the adjacent side edge of the link portion 28 at about the location of the inclined shoulder thereon so that continued radially outward movement of the link portion 28 will cause the carrier I8 to move longitudinally in a direction away from the axis of the motor pulley 25 whereby the tire 22 will be moved free of the motor pulley. Thus, the wheel 2| is moved in a positive manner to the position shown at Figure 4, wherein the tire 22 is free and clear of both the motor pul ley and the turntable flange. Upon the link 21 being shifted in the opposite direction to the full line position shown in Figure 1 the retraction of the link portion 28 allows the spring 24 to control the position of the adjacent friction or idling wheel whereby the motor pulley 25 is again operatively coupled with the turntable. At the same time the wheel 2| which is associated with the motor pulley 26 is moved to an operative free position. The means for shifting the link 21 will now be described.

Extending upwardly from a raised portion 34 of the plate l0 (Figure 3) is a flanged pivot pin 35 which mounts a bell crank lever 36, the outer free end of which projects under and outwardly of the periphery of the turntable while the inner end is trifurcated with the central trifurcation bulged and rounded as shown at 31 for limited rotational and slidable reception in a slot 38 formed in the link 21. The end trifurcations 39 and 49 are bent oppositely out of the plane of the link 21 and lever 36 so that the trifurcation 39 overlies the top surface of the link 27 while the trifurcaticn 4t underlies the bottom surface of the link 21, all as shown in detail in Figures 3 and 4. This arrangement guides the central trifurcation 31 and insures proper interengagement of the same with the side edges of the slot 38 as will be understood.

Secured to and depending from the plate In is a switch 4| preferably of the snap acting type and having a slidable operator 42 which projects upwardly through an aperture 43 formed in the lever 35 intermediate the trifurcated end thereof and the pivot pin 35. Switch 4| is so constructed that the operator 42 has linear movement with three aligned positions, the center of which is an off position with neither of the motors H and |2 energized. Through suitable wiring, not shown, the switch is so connected that when the operator 42 is moved to its right position as viewed in Figures 1 and 2, the motor II is energiZed while the motor |2 is de-energized. When moved to its extreme left position the motor H is de-energized while the motor I2 is energized. Thus, the control lever 36 is operative to deenergize both the motors or to selectively energize either of them while simultaneously and synchronously shifting the link 21 to remove the particular friction wheel not in use from both its associated motor pulley and turntable flange.

It should be observed that with the control lever 36 in its center or neutral position wherein the switch operator 42 is in its center position to de-ener-gize both motors the shift link 21 will likewise be in a neutral or center position. When in such position, however, both the friction wheels will be free and clear of their respective motor pulleys and of the turntable flange due to the fact that the overall length of the link 21 is greater than the spacing between the two lugs 32 of the respective wheel carriers Hi. The elongated nature of the link portions 28 and particularly of the side edges thereof which engage the'members [8 allows considerable over-travel in either direction from a neutral or central po- 7 5' sition so that by shifting the lever 36 in one direction fromiitsrneutral position one :of'zthe friction wheels will be lmaintainedyin :free and operative position while the other-is released Vfor engagement with the turntable flange and its associated motorpulley.

Theside edges of the slots 29 in the link 27 closest "to the carriers 1'8 are 'each formed with a notch Ml which is arranged tot-partially receive the shank of the adjacent guide stud 39 when thelink 23 ,is moved to center orineutralposition; It should be noted that when the link '21 the projection 32 of both the carriers i 8 is bearing against the side edges of the extension 28 inwardly of the rounded corners 32. Since the carriers l8 are yieldingly urged to rotateby the-springs 24 a yielding force ismaintained on the end portions 1&8 tending to move the same sideways whereby the notch 44 will be retained about the shank of the stud 39.- .In this manner the link 2'! is releasably latchedin center or neutral-position.

lt should now be apparent that I have provided an improved dual-speed phonograph turntable driving assembly utilizing a pair of driving motors imum substantial economies in production can be effected. Further, by arranging various separate parts to ea'chperform a number of functions the overall mechanism is rendered extremely simple in designand, dependable in continued use. Of particular importance is the provision of the may be properly controlled While in all cases the friction or idling wheel or wheels for the particular motor or motors which is not in use is formation 'of any deleterious flat spots on the tires of the "wheels. "The matter of uniform rotationalspeed'is'quite'important for high fidelity reproduction of phonograph records and is of especial importance eration of low-speed record systems.

The above specifically described embodiment of the invention should be considered as illustrative only as obviously many changes may be made therein without departing from the spirit or scope of the invention. Reference should therefore be had to the appended claims in determining the scope of the invention.

Iclaim:

l. A driving assembly for a flanged turntable comprising in combination a pair of spaced motor-driven shafts rotatable about axes generally parallel With the axis of rotation of the turntable and each having a driving pulley at its upper end, a friction wheel interposed between each pulley and the flange of said turntable, spring-biased movable carriers for said to retain each of said wheels in contact with said flange and said carriers remains spring-biased to maintain the wheel carried thereby in said yielding pressure :acontazct :with flange and its adjacent pulley.

1:2..Apparatusaocording to claim l'further characterized .in :ithat said shifting :mechanism is of flange-andsaid-pulleys. V 3. Aidriving ,assemblyrfora flanged 70f -.said turntable and an adjacent {one -of said pulleys, a spring for each of said carriers having one end connected to said plate (and thelotherend connected .to the carrier whereby the carriers are spring-biased to move 5. Apparatus according to claim 3 further characterized in -,-that-ea-ch of said carriers is said spring and when so moved being operative to transmit force whereby said edge and notch is maintained in pressure contact with said stud.

'7. A driving assembly for a flanged turntable comprising in combination a pair of spaced motor-driven shafts rotatable about axes generally parallel with the axis of rotation of the turntable and each having a driving pulley at its upper end, a mounting plate, a pair of carriers movably mounted on said plate, a friction wheel journaled on each of said carriers and arranged to be brought into yielding engagement with the flange of said turntable and an adjacent one of said pulleys, a spring for each of said carriers having one end connected to said plate and the other end connected to the carrier whereby the carriers are spring-biased to move said wheels into engagement as aforesaid, a movable link guided on said plate for engaging said carriers to move either or both of said carriers in opposition to the force or forces exerted by said spring or springs, a ferrule projecting upwardly from said plate about each of said shafts, said carriers comprising flat plate-like members having elongated apertures to receive the shanks of said ferrules whereby said carriers may have sliding as well as rotational movement with respect to the axes of said ferrules, said link and said carriers being mounted in a common plane, each of said carriers having an integral rounded projection on its outer corner adjacent its mounting ferrule, each of the outer ends of said link having a rounded corner to engage said projections and also having a stepped side edge adjacent said comer whereby upon sliding movement of said link in a general direction toward one of said carriers the said one of said carriers will be rotated and moved rectilinearly to withdraw the friction wheel mounted thereon from both said flange and the adjacent one of said pulleys while upon sliding movement of said link in the opposite direction the other of said carriers will be similarly actuated.

' 8. A driving assembly for a flanged turntable comprising in combination a pair of spaced motor-driven shafts rotatable about axes generally parallel with the axis of rotation of the turntable and each having a driving pulley at its upper end, a mounting plate, a pair of carriers movably mounted on said plate, a friction wheel journaled on each of said carriers and arranged to be brought into yielding engagement with the flange of said turntable and an adjacent one of said pulleys, a spring for each of said carriers having one end connected to said plate and the other end connected to the carrier whereby the carriers are spring-biased to move said wheels into engagement as aforesaid, a movable link guided on said plate for engaging said carriers to move either or both of said carriers in opposition to the force or forces exerted by said spring or springs, a ferrule projecting upwardly from said plate about each of said shafts, said carriers comprising flat plate-like members having elongated apertures to receive the shanks of said ferrules whereby said carriers may have sliding as well as rotational movement with respect to the axes of said ferrules, the side edges of said link and the end edges of said carriers adjacent said ferrules being so formed that upon the initial engagement of either end of said link with a carrier the carrier engaged is first caused to be rotated and thereafter to be moved rectilinearly in a direction away from the contacting link end.

9. Apparatus according to claim 8 further characterized in that the formed side edges of the end portions of said link are elongated whereby said link may have appreciable over-travel after a previously engaged carrier has been rotated and moved linearly as aforesaid.

WILTON E. BOYD, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS